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Title: Detection of enhancement in number densities of background galaxies due to magnification by massive galaxy clusters

We present a detection of the enhancement in the number densities of background galaxies induced from lensing magnification and use it to test the Sunyaev-Zel'dovich effect (SZE) inferred masses in a sample of 19 galaxy clusters with median redshift z≃0.42 selected from the South Pole Telescope SPT-SZ survey. Two background galaxy populations are selected for this study through their photometric colours; they have median redshifts z median≃0.9 (low-z background) and z median≃1.8 (high-z background). Stacking these populations, we detect the magnification bias effect at 3.3σ and 1.3σ for the low- and high-z backgrounds, respectively. We fit NFW models simultaneously to all observed magnification bias profiles to estimate the multiplicative factor η that describes the ratio of the weak lensing mass to the mass inferred from the SZE observable-mass relation. We further quantify systematic uncertainties in η resulting from the photometric noise and bias, the cluster galaxy contamination and the estimations of the background properties. The resulting η for the combined background populations with 1σ uncertainties is 0.83 ± 0.24(stat) ± 0.074(sys), indicating good consistency between the lensing and the SZE-inferred masses. We also use our best-fit η to predict the weak lensing shear profiles and compare these predictions with observations,more » showing agreement between the magnification and shear mass constraints. Our work demonstrates the promise of using the magnification as a complementary method to estimate cluster masses in large surveys.« less
 [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [1] ;  [7] ;  [1] ;  [1] ;  [1] ;  [8] ;  [1] ;  [1] ;  [9] ;  [10] ;  [1] ;  [11] ;  [12] more »;  [1] ;  [3] ;  [13] ;  [6] ;  [14] « less
  1. Ludwig-Maximilians Univ., Munich (Germany); Excellence Cluster Universe, Garching (Germany)
  2. Ludwig-Maximilians Univ., Munich (Germany); Excellence Cluster Universe, Garching (Germany); Max Planck Institute for Extraterrestrial Physics, Garching (Germany)
  3. Argelander-Institut fur Astronomie, Bonn (Germany)
  4. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Univ. of Chicago, Chicago, IL (United States)
  5. Univ. of Chicago, Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
  6. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Harvard Univ., Cambridge, MA (United States)
  7. Univ. of Chicago, Chicago, IL (United States)
  8. Univ. of Florida, Gainesville, FL (United States)
  9. Leiden Univ., Leiden (The Netherlands)
  10. Stanford Univ., Stanford, CA (United States); Univ. of of Copenhagen Juliane Maries Vej, Copenhagen (Denmark)
  11. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
  12. Univ. of Melbourne, Parkville (Australia)
  13. Ludwig-Maximilians Univ., Munich (Germany)
  14. Cerro Tololo Inter-American Observatory, La Serena (Chile)
Publication Date:
Report Number(s):
Journal ID: ISSN 0035-8711; arXiv eprint number arXiv:1510.01745
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Monthly Notices of the Royal Astronomical Society
Additional Journal Information:
Journal Volume: 457; Journal Issue: 3; Journal ID: ISSN 0035-8711
Royal Astronomical Society
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Orgs:
SPT Collaboration
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; gravitational lensing: weak; galaxies: clusters: individual; cosmology: observations; large-scale structure of Universe
OSTI Identifier: